InfluxDB学习(一)：基本概念和安装

一. InfluxDB数据库介绍

InfluxDB是Influxdata旗下开源的一种时序数据库(Time Series Database)，根据DB-engine排名，目前在time series数据库领域排名第一位。

InfluxDB下载地址

https://portal.influxdata.com/downloads/

InfluxDB排名

https://db-engines.com/en/ranking/time+series+dbms

 InfluxDB主要功能

1. 对时序数据(sereis data)使用TSM存储引擎，提供高性能的数据写入和压缩功能。
2. go语言编写，程序只有一个二进制的可执行文件，没有其他依关系。
3. 通过http API可提供高性能的便捷的读写操作。
4. 插件支持采集Graphite, collectd, and OpenTSDB等数据源。
5. 提供类似SQL语法格式的数据操作。
6. 保留策略(retention policies)功能可以定期清除老旧数据。
7. 不间断(continuous queries)自动化查询功能统计聚合数据来使数据查询更有效率。

缺点：

1. 社区版只支持单机部署，集群功能需要使用收费的企业版。
2. InfluxDB中文学习文档较少，对于想要了解该数据库的用户有一定的不便。

InfluxDB与RDBMS中的概念比较

二. InfluxDB数据库安装

# mkdir /usr/local/influxdb
# groupadd -r dba
# useradd -r -g dba tnuser
# chown -R tnuser.dba /usr/local/influxdb
# sudo su - tnuser
$ cd /usr/local/influxdb
$ wget https://dl.influxdata.com/influxdb/releases/influxdb-1.8.0-static_linux_amd64.tar.gz
$ tar -zxf influxdb-1.8.0-static_linux_amd64.tar.gz
$ mv influxdb-1.8.0-1/* .
$ rm -rf influxdb-1.8.0*

使用CentOS7的systemctl管理InfluxDB服务

# cat /usr/lib/systemd/system/influxdb.service 
[Unit]
Description=InfluxDB is time series database
Documentation=https://docs.influxdata.com/influxdb/v1.8/introduction/get-started/
After=syslog.target
After=network.target

[Service]
Type=fork
User=tnuser
Group=dba
Restart=always

# Disable OOM kill on the Redis
OOMScoreAdjust=-1000
Environment=PG_OOM_ADJUST_FILE=/proc/self/oom_score_adj
Environment=PG_OOM_ADJUST_VALUE=0

ExecStart=/usr/local/influxdb/usr/bin/influxd
ExecStop=/bin/kill -15 $MAINPID
LimitNOFILE=65536
 
[Install]
WantedBy=multi-user.target

# systemctl daemon-reload
# systemctl enable influxdb
# systemctl start influxdb
# systemctl status influxdb
● influxdb.service - InfluxDB is time series database
   Loaded: loaded (/usr/lib/systemd/system/influxdb.service; disabled; vendor preset: disabled)
   Active: active (running) since Sat 2020-04-18 23:19:03 PDT; 1s ago
     Docs: https://docs.influxdata.com/influxdb/v1.8/introduction/get-started/
 Main PID: 22583 (influxd)
   CGroup: /system.slice/influxdb.service
           └─22583 /usr/local/influxdb/usr/bin/influxd

Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.203421Z lvl=info msg="InfluxDB starting" log...568f5
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.203467Z lvl=info msg="Go runtime" log_id=0MG...ocs=4
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.311597Z lvl=info msg="Using data dir" log_id.../data
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.311635Z lvl=info msg="Compaction settings" l...31648
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.311647Z lvl=info msg="Open store (start)" lo...start
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.553803Z lvl=info msg="Reading file" log_id=0...87843
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.572851Z lvl=info msg="Opened file" log_id=0M...749ms
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.594031Z lvl=info msg="Opened file" log_id=0M...915ms
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.610554Z lvl=info msg="Opened shard" log_id=0...256ms
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.612039Z lvl=info msg="Opened shard" log_id=0...741ms
Hint: Some lines were ellipsized, use -l to show in full.